Today's advanced communication devices are capable of seamlessly operating in a packet-switched IP network domain (using, for example, wireless LAN (WLAN) or Wi-MAX networks) as well as a circuit-switched cellular network domain. To facilitate such capability, current 3rd Generation Partnership Project (3GPP) standards specify a new, IP-based network architecture referred to as the IP multimedia subsystem (IMS) which allows a communication device (referred to as user equipment or UE) to initiate calls to both IP-only subscribers and conventional circuit-switched telephony subscribers using either one of the domains. There may arise a situation, however, where a wireless device (i.e. a UE device in 3GPP) is able to make a voice call to a called party through only the circuit-switched cellular network domain because either no packet-switched IP network is available, the available networks in the packet-switched domain do not support the Voice-over-IP (VoIP) service, or the user preference/subscriber policy prevents usage of the packet-switched domain for some or all services. In such a situation, if the called party happens to be an IP-only subscriber and is identified with a Uniform Resource Indicator (URI), the originating UE device may not be able to make the IP-based call since the UE device can effectuate only E.164 number-based calls while operating in the circuit-switched cellular network domain.